Method of removing ink from paper-stock.



r'r mans near rare MAX CLINE AND CHARLES F. RHODES, OF GLENS FALLS, NEWYORK, ASSIGNORS TO INTERNATIONAL PAPER COMPANY, OF NEW YORK, N. Y., A

CORPORATION OF NEW Patented May 4, i915.

. YORK.

I METHOD OF REMOVING" INK FROM PAPER-STOCK.

1 ,138 Q 85. Specification of Letters Patent.

No Drawing.

To all whom it may concern: Be it known that we, MAX GLINE and CHARLESF. Rnonns, citizens of the United skilled in the art to which itappertains to make and use the same.

This invention relates to a certain new and useful improvement in theremoval of printers ink from old paper stock, that is to say from stockmade up in whole or in part ofwaste printed-paper, as, for instance,from old newspapers, printed books, and the ike; I

In the practice of the invention, the waste paper stock is macerated inthe presence of water in a beater engine or any machine for reducing itto a substantially homogeneous pulp. To the original or macerated stock,containing the ink to be removed, is added a caustic alkali, insolution, preferably caustic soda, which has the effect of lifting theink from the fiber. There is also added to the original or maceratedstock a quantity of silicate of aluminum such as fullers earth, kaolinand all other clays or silicate of magnesium such as talc, soapstone,etc., which serve to take up, absorb, or carry the ink, therebysegregating it from the fiber. Finally, by a washing operation, thealuminum silicate or clays, carrying with it the ink, is separated fromthe fiber, thereby bringing the stock back quite closely to the originalcondition and color of raw stock.

As an illustration of the successful practice of the invention, it maybe stated that successful results may be obtained by first maceratingthe waste printed paper stock or book stock with the necessary amount ofwater to bring it to a pulp. This operation can be carried on in abeater engine or in any other suitable type of pulping machine, and withwater at ordinary atmospheric temperatures. To the macerated or pulpedstock is then added the caustic alkali and the absorbing agent, in theproportion of,

Application filed November 27, 1911. Serial No. 662,579.

say, forty pounds of caustic soda (sodium hydrate), and forty pounds ofaluminum silicate or clay, per ton of the pulped stock of beaterconsistency. The caustic alkali thereupon exercises its function oflifting the ink from the fiber ofthe stock and the aluminum silicate orclay is found to absorb, take up, and carry the ink, thereby segregat ngit fromthe fiber. The operation is facilitated and made uniform byvigorously agitating and mixing the mass for a period varying from sayten minutes to thirty mlnutes according to the character of the stockemployed and the desired completeness of the result. In some instances,also, it may be further facilitated by raising the temperature of thestock by the injection of steam or the addition of hot water. Thereuponthe aluminum silicate or clay, carrying the ink, is washed from thefiber in any suitable manner, as, for instance, in the drum washer incommon use in paper mills, in which also the stock may be macerated,treated and washed, or by any other washing method desirable.

What we claim is:

1. The process of removing ink from waste newspaper stock, book stock,and the like, which consists in pulping the stock, adding a causticalkali thereto for lifting the ink, adding aluminum silicate or clay, toabsorb the lifted ink, and washing out the ink-carrying absorbent;substantially as described.

2. The process of removing ink from wastev newspaper stock, book stock,and the like, which consists in pulping the stock, lifting the ink byadding about 2% of caustic soda, absorbing the lifted ink by add;

